For rigid flooring materials, locking mechanisms have been used for connecting flooring pieces together for over a century. For example, U.S. Pat. No. 1,978,075 to Butterworth describes wood block flooring with a tongue and groove engagement system for securement of such blocks in side-by-side relationship. U.S. Pat. No. 2,914,815 by Alexander shows an interlocking flooring system wherein individual blocks have offset base members formed of plywood. U.S. Pat. No. 3,554,850 to Kuhle shows parquet flooring with projecting parts for side-by-side securement of similar parquet sections. U.S. Pat. No. 3,914,913, issued to Roberts, discloses a snap interlock deck structure of extruded aluminum. U.S. Pat. No. 3,731,455, issued to Hoffmann et al., discloses floor tiles joined together by cutting away material along the edges thereof so as to leave downwardly-extending undercut projections. The tiles are joined together by using a strip having a pair of channels which receive the projections from two different tiles. U.S. Pat. No. 5,179,812, issued to Hill, discloses a wood panel having a plurality of aluminum battens connected to the base of the panel. U.S. Pat. No. 5,052,158, issued to D'Luzansky, discloses a modular locking floor covering having panels with interlocking means composed of spaced locking fingers and locking apertures and secondary locking means in the form of tabs in the face of the finger and the base of the aperture. Each tab has a face inclined in a direction opposite to the inclined face of an adjacent tab.
Another interlocking design is disclosed in U.S. Pat. No. 5,050,362, issued to Tal et al., which discloses construction panels for roofing and the like that become locked to define a connection which is highly resistant to both clockwise and counter-clockwise movements applied about a connection axis. U.S. Pat. No. 3,538,819, issued to Gould, discloses air field matting having interlocking members. Further, U.S. Pat. No. 4,845,907, issued to Meek, discloses interlocking panel modules usable for decking sections in poultry operations.
An example of a mechanism that is commonly used for securing flooring blocks is set forth in U.S. Pat. No. 5,797,237, issued to Finkell, Jr. This reference describes a snap-together flooring system which fixes adjacent flooring members from lateral movement with respect to one another. A first flooring member includes a channel having a downwardly extending barb. A second flooring member includes an outwardly extending tongue having a groove defined therein. The first and second flooring members are snapped together by moving the tongue into the channel, which causes the barb to ride upwardly on an inclined face of the tongue in an elastic manner, and to ultimately snap downwardly into place within the groove of the tongue. The engagement of the barb in the groove of the tongue prevents laterally removal of the tongue from the channel, and thus holds the adjacent flooring members together. Disengagement of the flooring members is provided by lifting of the interface between the adjacent flooring members and rotating the flooring member having the tongue downwardly in order to disengage the barb from the groove of the tongue, and to thus allow extraction of the tongue from the channel. U.S. Pat. No. 7,591,116 to Thiers et al. is for packaging flooring panels that also includes a locking design similar to Finkell's.
U.S. Pat. No. 7,856,785 to Pervan discloses a tongue for both the long side and the short side as well as a locking groove also for both the long and short sides of a panel. The system is for laminate floor panels that have a harder decorative surface layer than the core layer beneath.
With respect to flexible flooring materials, one potential disadvantage of rigid flooring materials is that they do not conform to the contours of the hard floor surface. The mitigating measures could be expensive and complicated to apply. Flexible materials of rubbery or plastic types are then utilized for such applications. British Pat. No. 812,617 discloses flooring having rubber members of rectangular or square shape. Adjacent members are engaged with one another by a snap action through pressure directed perpendicularly to the joint line between the adjacent members. U.S. Pat. No. 7,155,871 describes how two floor panels of two layers of flexible plastic sheet material laminated together in offset relationship to define an offset marginal portion for each of the layers are jointed together. Each of the offset marginal portions has oppositely facing adhesive coated surfaces. A foam layer and/or a fiberglass sheet can also be included in the laminate structure of the floor panel. The floor panel can conform to surface contours of a floor base. The bottom layer of the floor panel, whether it is plastic sheet or foam, is conformable to surface irregularities of the floor base. A one piece releasable packaging device covers the oppositely facing adhesive coated surfaces of the offset marginal portions.
Regarding other interlocking systems, there may be drawbacks associated with flooring locking mechanisms. U.S. Pub. No. 2008/0184647 discusses a fabricated hardwood flooring product which is to provide an advantage of a thick wood wear layer, similar to a traditional ¾-inch solid wood floor, with the dimensional stability characteristics of engineered wood flooring products. An interlocking design has also been set forth in U.S. Pub. No. 2009/0031662, in which a floor panel includes a first sheet having four sides. The first sheet has an upper surface and a lower surface, and the first sheet includes at least one base layer and a print design located above the base layer. At least one wear layer is located above the print design. Furthermore, a second sheet has multiple sides and having an upper surface and a lower surface, and the upper surface of the second sheet is adhered to the lower surface of the first sheet. Two adjacent sides of the second sheet have multiple projections to interlock with recesses from at least one adjacent floor panel, and two other adjacent sides have recesses to interlock with projections from at least one adjacent floor panel. The projections and recesses have a complementary shape to each other to be interlockingly engageable with corresponding recesses or projections on an adjacent floor panel. The multiple projections of the two adjacent sides of the second sheet extend beyond two adjacent sides of the first sheet, and the recesses of the two other adjacent sides of the second sheet do not extend beyond the first sheet and are concealed by the first sheet. At least a portion of the lower surface of the first sheet that is located directly above the recesses have at least one adhesive coating that permits adhesion of an upper surface of a projection from an adjacent floor panel or the upper surfaces of the projections have an adhesive coating or both.
U.S. Pub. No. 2009/0064623 relates to a double-layered floor panel sheet having a non-adhesive portion, and more particularly to a floor panel sheet enabling adjustment of position during installation. When the upper layer of a floor panel sheet is bonded to the lower layer of another floor panel sheet, a non-adhesive portion formed in part of an adhesive portion enables the adjustment of position. An application specifically for bamboo flooring panels with glueless locking system was set forth in U.S. Pub. No. 2008/0141611. This reference provides a 100% bamboo panel with an interlocking system and associated manufacturing methods. In one embodiment, the 100% bamboo panel includes first, second, and third layers of 100% bamboo, wherein the layers are laminated together. The layers are independently preconditioned to control moisture content therein. Each layer can be preconditioned by alternately elevating and lowering the moisture content in a plurality of sequential cycles before the layers are laminated together. The middle layer is oriented so its grain is substantially perpendicular to the edges of the panel. The panel has joinery portions formed along the edges, and joinery includes an asymmetric upper joinery member and lower joinery member arrangement for, and at least a portion of the upper joinery member and lower joinery member portions are formed in the second layer.
U.S. Pub. No. 2009/0183458 describes a paneling system preferably for floors defined by a series of panels each formed of a plurality of tongue and groove main floor panel strips arranged side edge to side edge and cut to a common length with a tongue along one cut edge and a groove along the other. At the edges are attached edge strips formed also from the flooring panels with tongue and groove and fastened together to form a common panel member for transportation and installation. The outwardly facing edge has a tongue or groove for mating with a groove or tongue of an adjacent panel. The strips are fastened by pins or corrugated plates from the rear or by a bonded sheet material on the rear. The strips may include tongue and groove joints of the snap fastening type where the connection of each strip to the next in the assembled panel can be simply by way of an adhesive tape over the rear surface of the joint.
Joining flooring pieces such as those described above may have drawbacks including that they may be difficult to make, and/or they may not be user friendly. In some instances they may not be cost effective in terms of manufacturing and/or installation. There may also be a potential for human error in the installation process. For instance, traditional adhesive systems for vinyl panel installation involve first preparing the floor, then applying adhesive the entire area to be covered, and finally laying the vinyl panels. However, this process may require relatively costly adhesive, and intensive installation labor. One approach intended to address such cost and inefficiency drawbacks is set forth in U.S. Pat. No. 7,155,871. Here, the adhesive is pre-applied by the manufacturer and may be covered with wax paper also. An installer would peel off the paper and put the male side on top of the female side, then push down and glue together.
Even so, this process may require that the installer be very careful when aligning the two pieces together before pressing them down, as gaps may otherwise form between the adjacent panels. When this happens, the already glued together panels have to be separated and realigned to complete the installation process. A significant disadvantage of this is that after the vinyl panels are pulled apart a couple of times, this may make the adhesive lose its original strength, and also make the installation process more frustrating.